Autoslash.com reviews?

Hi, We are planning a trip 12/3/12 to 12/15/12, I have been looking into car rental rates and most coupons and codes will not work for a trip that far out.
I have come across a website called autoslash.com, which automatically tracks rates for you. I was wondering if anyone out there has had experience using them. If you have used them in the past please let me know how things went. Thank you for your time everyone.

I have booked through Autoslash's website, but the trip has not occured yet. I booked way back last fall, and the prices did keep coming down. They were over $400 back then. They automatically rebook you and send you an email with the new price. (Subjectline: Great News!) I actually would go back to the website every once in a while just to check. One thing I noticed was that sometimes, if the price was lower at another company, they didn't always notice and switch you to another company. Now that I think about it, the autosash computers may not have noticed because it was a different car class (midsize vs. full size). As a result, I ended up booking 2 different reservations - one for a full size and one for a midsize. One is with Dollar and the other is with Advantage. One is down to around $130 and the other is around $150. This is for 8 days in April (14-22). Since they don't take your credit card and you cancel at anytime, my theory is it can't hurt to book with them, then between 6 weeks and a month out from your trip, start checking these boards to see what other deals are out there. Alamo recently came out with a rate of $130 for a full size (Alamo does not participate with Autoslash), so I booked that,too. I'm going to give it one more week to see if anything gets lower, then I'll choose one and cancel the other 2. Hope that helps!

Where did you find that great rate with Alamo? We are looking for April 3-14 and can't find anything under $500 except with Autoslash.com. I was interested in the comments about that site as well. We do have a back up at almost $400 for 10 days. That is still more than we usually pay.